// See LICENSE for license details.

package firrtl.constraint

object IsFloor {
  def apply(child: Constraint): Constraint = new IsFloor(child, 0).reduce()
}

case class IsFloor private (child: Constraint, dummyArg: Int) extends Constraint {

  override def reduce(): Constraint =
    child match {
      case k: IsKnown => k.floor
      case x: IsAdd   => this
      case x: IsMul   => this
      case x: IsNeg   => this
      case x: IsPow   => this
      // floor(max(a, b)) -> max(floor(a), floor(b))
      case x: IsMax => IsMax(x.children.map { b => IsFloor(b) })
      case x: IsMin => IsMin(x.children.map { b => IsFloor(b) })
      case x: IsVar => this
      // floor(floor(x)) -> floor(x)
      case x: IsFloor => x
      case _ => this
    }
  val children = Vector(child)

  override def map(f: Constraint => Constraint): Constraint = IsFloor(f(child))

  override def serialize: String = "floor(" + child.serialize + ")"
}
